Walking along one day on the newly-discovered coast of Australia, Captain Cook saw an extraordinary animal leaping through the bush."What's that?" he asked one of the aborigines accompanying him. "Uh - gangurru." he replied - or something like that. Captain Cook duly noted down the name of the peculiar beast as 'Kangaroo'. Some time later, Cook had the opportunity to compare notes with Captain King, and mentioned the kangaroo. "No, no, Cook", said King, "the word for that animal is 'meenuah' - I've checked it carefully. "So what does 'kangaroo' mean?" "Well, I think," said King "it probably means something like 'I don't know'..." But it was too late, and so ever since, the English word 'kangaroo' has been based on a misunderstanding, and really means 'I don't know'. At any rate, that's how the story (probably apocryphal) goes.

It may well have been this story which Quine had in mind when he came up with the 'Gavagai' example used in 'Word and Object'. The word has achieved a kind of fame in itself: there is now a species of beetle named after it, and it was used by Umberto Eco as the name of a minor character in his novel 'Baudolino'.

Quine was concerned to give a fundamental explanation of how we manage to use words: 'how surface irritations generate, through language, one's knowledge of the world'. He addressed in particular the problem of radical translation - how we can find a translation for words in an entirely unknown language which has no known correspondence with our own. Utterances such as 'ouch', he suggested, are relatively straightforward - the word properly corresponds with the occurence of pain. But other words, even nouns, do not correspond so exactly to the pattern of stimuli we happen to be experiencing at the time.

Suppose we have a linguistic explorer and a native subject: a rabbit runs past and the native exclaims 'Gavagai!'. The linguist forms the reasonable hypothesis that 'Gavagai' means 'rabbit', but how can he be sure? Putting aside some difficulties about 'yes' and 'no', he can ask the native in a series of different situations the simple question 'Gavagai?' and see what responses he gets. Quine wants to build up from 'stimulus meaning', which is equivalent to a list of all the stimuli which would prompt the native to say 'yes' in response to the stereotyped question, to more complex and natural kinds of meaning - 'occasion sentences' which are true in particular sets of immediate circumstances (eg when a rabbit is present) and 'standing sentences' which are true irrespective of what happens to be going on around us at the moment, for example.

But the upward path proves unexpectedly difficult. As a matter of fact, the native's tendency to agree may be influenced by extraneous factors - he may have seen a rabbit a few minutes before and hence be prepared to accept a mere rustling in the grass as sufficient evidence. Or he may observe a characteristic 'rabbit fly' unknown to the linguist which betokens the prescence of a rabbit even in the absence of any other evidence. Or perhaps he dissents, not because he thinks there isn't a rabbit, but because he presumes the linguist to be a hunter and there isn't at the moment a clear shot available. But even if we can get round these difficulties, there simply is no guarantee that any finite set of observations pin down the correct meaning of the word 'gavagai'. Even if we can establish identity if stimulus meanings, we cannot thereby verify 'intrasubjective synonymy' of 'gavagai' and 'rabbit'. The native may use the word in exactly those situations in which the linguist would use the word 'rabbit', but it could still mean something different: 'temporal section of a rabbit' or 'set of undetached rabbit parts'. For that matter, it could mean 'rabbit or dalek' or 'rabbit before the year 3000 and bear after that'. Ultimately Quine affirms the 'indeterminacy of translation' - we cannot provide certain radical translations (and since translation is, for Quine, much the same as understanding, we can never be sure we have correctly understood any linguistic utterance either).

A natural reaction to this disastrous conclusion is incredulity. Yes, of course, some degree of uncertainty attaches to everything; yes, we can always come up with a fantastic alternative meaning for any sentence which is logically consistent with the circumstances, but so what? We just know that in practice translation is possible. There are two things which can be said in reply.

First, problems of translation and misunderstanding are not as exceptional as all that. It would be entirely possible for an Englishman and an American to have lengthy conversations about robins without realising that the word refers to entirely different birds on different sides of the Atlantic (hence, in part, the bemusement which generally creeps over a British audience during one particular scene in 'Mary Poppins'); or indeed, to talk about turtles without realising that one used the word in a significantly more inclusive sense than the other. But second, Quine never denied that in ordinary conversation and translation we seem to manage pretty well - the question is how, exactly? It's not difficult to explain that once you have seen enough examples of the use of 'gavagai' the meaning becomes obvious - but stating exactly how it becomes obvious, and how all those implausible alternatives are recognised as implausible, is extremely difficult, as the creators of translation programs have found. One can liken Quine's attitude to translation to Hume's puzzlement over induction - it seems to work: indeed, without it we should be in grave difficulty, but why it works is an utter mystery.

To quote one last practical example, we can return to poor old Captain Cook. Although the legend of his misunderstanding still thrives, it appears from more recent research that in fact the word he heard all those years ago probably did mean 'kangaroo' in a particular local dialect after all. So what about Captain King's 'meenuah'? It turns out that the word he was reporting was probably one that meant, not 'kangaroo', but 'edible animal'...

_____The law provides us structure to guide us through paralyzing and trying times. But it requires us a vision to its procedures and higher purposes. Before we assume our respective roles in this enduring drama just let me say that when these frail shadows we inhabit now have quit the stage we'll meet and raise a glass again together in Valhalla.